Process of magnetic separation.



PATENTED APR. 10, 1906.

, F; T. SNYDER. PROCESS OF MAGNETIC SEPARATION.

APPLICATION FILED DEC. 20

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F. T. SNYDER. PROCESS OF MAGNETIC SEPARATION.

APPLICATION FILED DEO.20. 1902.

PATENTEDAPR. 10, 1 906.

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Frederick I? barren sra rns rarnnr ensign,

FREDERICK T. SNYDER, O1! OAK PARK, ILLINOIS, ASSIGNOR, BYMESNE ASSIGNMENTS, TO INTERNATIONAL SEPARATOR COMPANY, OF OHI- OAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

PROOEQS OF MAGNETIC SEPARA'E'EQNH Specification of Letters Patent.

Patented April 10. 1908.

Application filed December 29, 1902. Serial No. 136,005.

drawings, forming a part of this specification.

My invention relates to the magnetic separation of materials of different degrees of magnetic permeability.

Broadly stated, my in =eiition provides an improved process of magnetic separation inwhich the forces effective in making the separation are more efficiently controlled in strength, direction, and duration of application.

In'my improved process a mass of materials is subjected to a number of attractive impulses applied in different directions and at different places. The more permeable materials are attracted from the materials to be separated toward the place of convergence of a magnetic flux, the convergence and attracted materials being then given a comparatively small movement relative to non attracted materials. At the end of the movement the attracted materials are released and deposited by sufficiently reducing either the density or the convergence of tho flux passing through the materials. The more permeable materials are then again .attracted toward a place of convergence of a magnetic flux and given a second and additional movement. This cycle of operations is repeated until a sufficient relative movement between attracted and unattracted materials is attained.

1n practicing my invention 1 iind it desirable to release the attracted materials for deposit by reducing to zero the density of the flux through the convergence. This minimum density of the flux may be secured by reversing thr. polarity of the flux through the convergence, the density of the flux at the time of reversal being zero. At this time of reversal materials of the greatest attractability will be released.

My improved process is particularly useful in the separation of materials of very low permeability. In the separation of such materials the necessarily high density of the magnetic force required may be attained in a field between two poles of opposite polarity which closely approach each other.

In a copending application, Serial No. 136,004, filed December '20, 1902, I have illustrated and claimed apparatus adapted to carry out the processes herein more fully described.

he features of my improved process may be explained by reference to a device for carrying out the process illustrated in the accompanying drawings, in which- Figure 1 is a front elevation of a separator embodying my invention. Fig. 2 is a plan View of the same. Fig. 3 is a cross-sectional view taken on line 3 3 of Fig. 2. Fig. 4 is a sectional view taken on line 4 4 of Fig. 1.

In this apparatus for carrying out my in-'' vention I have shown a pair of cast-iron frame-plates 6 6, adapted to be clamped together by the bolts 7 7 to hold in position the laminations of the field-magnet 8. This iicldmagnet is provided with oppositely-disposed pole-pieces 9 and 10, whose faces respectively, constitute poles 11 and 12. An energizing-winding 13 is wound on the fieldrnagnet, desirably about the pole-piece 9. The springs 14 14 support the table or armature 15 between the poles 11 and 12. The armature, like the field-magnet, is desirably made of laminated-iron punchings, as best illus trated in Fig. 4, the punchings being held in positionb y means of a brass or bronze clamping-frame, comprising side rails 16 and 17,

having dovetailed connection with the arma ture laminations and end rails 18 and 19, to which the supporting-springs 14 are fastened. The bolts 20 2O serve to clamp the frame tightly about the laminations forming the armaturem The side rail 17 may desirably have its upper edge beveled, as best illustrated in Fig. 3, the purpose of which will hereinafter more fully appear.

The upper pole 11 is formed into projections 21, which may take the form of wedgeshaped teeth. Through the polepiece 9 there leads a chute 22, through which materials to be separated are fed to the gap of low permeability between the pole l1 and the armature 15. The tapering hoppers 23 and 24 are placed one on either side of the pole-piece 10 and, as will hereinafter be explained, serve to convey separated materials from the machine. The operation of my improved separator 5 will now become apparent. A pulsating or preferably alternating current of comparatively low frequency is supplied to the energizing-winding 13. It will be noted that the pole-piece is placed considerably to the left of the iron armature 15, also that the lower edge of the armature extends slightly to the'right of the pole-piece 10. The result of this unsymmetrical placement of the .armature is that when the field-magnet is energized the magnetic flux in the air-ga between the poles 11 and 12- causes a resultant attraction of the armature 15 toward the left. The su porting-springs 14 permit a movement 0 the armature to balance'the forces of attraction. It will be seen that the successive ma netizations and demagnetizations of the field-magnet on account of the alternating currents supplied to the winding 13 will cause successive attractions of the armature, the resiliency of the springs serving to retract the armature into its normal position between attractive impulses. Thus the armature receives and maintains an'oscillatory or reciprocal motion. Materials to be separated are fed through the chute 22 to the upper surface of the armature 15. One of the purposes of 'the oscillatory movement of the armature is to causcfa mechanical shake or movement of materials to be separated toward the hopper 24. This movement of materials may be secured, by a sudden stopping of the movement of the armature toward the left and a consequent rebound or quick-return movement toward the right. For this purpose 1 provide projections 35 and 26 on the armature framepieces 18 and 19, these projections being adapted to come into contact with enlargements 2? and 28 on the frame-pieces 6 '6. It will be seen that the accelerated movement of the armature toward the left and the abruptstopping of the same, due to the impact of the projections 25 and 26 upon the enlargements 27 and 28, will cause a shaking moven'ient toward the left of materials rest- 50 ing on the armature. I refer to this peculiar movement of the armature which causes a shaking of materials resting thereupon in one direction as a differential movement, and I define a differential reciprocating movement of any form ofarmature or shaking table to mean a reciprocating. motion such that materials resting upon said armature or table are given an absolute net resultant movement with respect to such armature or table. As the pole-pieces become energized there is produced a magnetic flux locally convergent toward each of the projections 21 and correspondlngly divergent toward the plane-induced pole constitutmg the upper face of the 6 5 armature 15. The projections 21 are so was shaped and laced at such a distance from the upper po e of the armature that the more permeable materials fed to the armature are attracted toward the projections. Since there is considerable inertia to be overcome in starting the movement toward the left upon the energization of the field-magnet, the more ermeable materials resting on the upper sur ace of the armature are attracted toward the teeth 21 before the armature has acquired any considerable movement toward the left. Upon the deenergization of the field-magnet with the reversal of the direc-- the reversed direction. The successive repetition of this cycle of operations results in carrying the more permeable materials in successive steps toward the right. It will be remembered that the movement of the armature toward the left is brought to an abrupt termination, thereby throwing the nonattracted materials resting on the armature toward the outer edge of the clamping-rail 16,

IOC

over which the materials may fall into the receiving-hopper 24. As the more permeable materials are carried to the right-hand edge of the pole 11 they are attracted toward the teeth projecting from this right-hand edge of the pole, from which position they are released to fall on the beveled or sloping edge of the clamping-rail 17, this sloping edge serving to guide the deposited materialsinto the receiving-hopper 23.

It will be seen that due to the quick-return motion of the table the non-attracted mate rials are given a net movement toward the left, while the step-by-step advancement of a the attracted materials results in anet movement toward the right.

A direct pulsating current supplied to the winding 13 would have an effect similar to that of the alternating current. It will also be apparent to those skilled in the art that the quick-return or bumping motion of the armature might be controlled by mechanical means suitably operated in s nchronisi'n with the electrical impulses supp ied to the winding 13 and also that a separationmight be accomplished by a positive movement of the projections 21. j

When a secondary electromagnetic means or a mechanically-operated means is employed to cause the reciprocal movement of d ying out my invention,

the materials witn rei'erence L; Lilo poie piece Qgit. be apparent that a table of nonmagnetic matenalmight be substituted for the iron armature 15.

the. movements in the reverse direction,

whereby the attracted materials are iven a net movement in one direction, and t e nonattracted materials are given a not movement in another direction.

2. The rocess of magnetic separation, which consists in causing a differential reci rocating movement between materials to e separated, and a convergence of a magnetic flux, decreasing the density of the flux through the convergence during the move-- ments in one direction, and increasing the density of the flux through the convergence during the movements in the reverse direction, whereby the attracted materials are given net movement in one direction, and the non-attracted materials are given a net movement in another direction. I

3. The process of magnetic separation, WlliCll consists in causing a diiierential reci rocating movement between materials to e separated, and a convergence of'a magnetic flux, decreasing to zero the density of the iiux through the convergence during the movements in one direction, and increasing the density of the flux through the convergence (hiring the movements in the reverse direction, whereby the attracted materials are given a net movement in one direction, and the non-attracted materials are given a net movement in another direction.

4-. The recess of magnetic separation, which consists in causing a differential reci roosting movement between materials to e separated, and a convei ence of a magnetic flux, reversing the p0 arity of the flux through the convergence during the movements in one direction, whereby the attracted materials are iven a net movement in one direction, and t e non-attracted materials are given a net movement in another direction.

5. The method of ma ores, which consists in itierentiallyreciprocating the ores Within the influence of a mag net, periodically energizing and deenergizing the magnet, and 'maintaining synchronism between the reciprocations and the changes in the field of the ma net.

6. The process 0 which consists in causing a relative differential reciprocating movement of materials-to be separated with respect to the place of convergence of a magnetic flux, reversing the netically separating polarit of the flux to said place of convergence uring the movements n one direction, I and maintaining the continuity of the flux to said place of convergence during the movements in the reverse direction, attracted materials are iven a net movement in one direction an the non-attracted materials are given a net movement in another direction.

7. The process of magnetic separation,

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I Witnesses":

LYNN A. WILLIAMS,

HARVEY L. HANsoN.

whereby the I which consists in imparting to the mass of" magnetic separation, 

